Partial polarization of light induced by random defects at surfaces or bulks

Abstract

Partial polarization may be the result of a scattering process from a fully polarized incident beam. It is shown how the "loss of polarization" is connected with the nature of scatterers (surface roughness, bulk heterogeneity) and on the receiver solid angle. These effects are theoretically predicted and confirmed via multiscale polarization measurements in the speckle pattern of rough surfaces. "Full" polarization can be recovered when reducing the receiver aperture.

Characterization and cleaning control of optical coatings by using a goniometric light scatter instrument with sample imaging ability

“…Finally, the theoretical principles behind this roughness measurement method are clearly compatible with other spectral studies (wavelength switching of incoherent sources) and polarization analysis, as previously defined by our team on a standard ARS instrument [20][21][22].…”

Separation of surface and bulk reflectance by absorption of bulk scattered light

“…Angle-resolved ellipsometry has proved to be a successful technique, although the method becomes increasingly complex when analyzing highly scattering materials with significant surface roughness [23][24][25][26]. A completely different approach is to coat the surface of the sample with a thin opaque metallic layer, thereby blocking the bulk reflectance [27].…”

Angle-resolved ellipsometric data for selective imaging in scattering media

“…With a fully polarized incident plane wave, each ray scattered at any direction (θ,φ) at infinity can be associated with a perfectly polarized plane wave of complex vector amplitude A = (A S , A P ), with A S and A P two polarization vector modes. In a first step we here assume that the variations of polarization versus direction are rather low within the receiver solid angle under study, which allows us to neglect any loss of polarization [1], that is, to consider the full polarization regime [2,3]. Hence if we introduce retardation and analyzer plates on the scattered beam, the resulting field can be written as:…”

“…Relation (1) shows that all plane waves A(θ,φ) perpendicular to u * (ψ,η) have a zero image by the f transformation, that we call an "ellipsometric zero". Such zero is reached when the following condition is fulfilled: z ( ψ,η) = -A S /A P (θ,φ) (2) with z(ψ,η) = tgψ e jη the complex number that we associate with vector u(ψ,η).…”